Scientific Production of Some Acids. 71) 



Silicates may have several formulae. Those to which I 

 am about to refer are the meta-silicates, whose types are 



M, Si 3 and M Si 3 ; M and M respectively, indica- 

 ting univalent and bivalent basylous radicals, one atom of 

 the latter, or two of the former, being saturated by the 

 diabasic silicic radical. 



To illustrate the process for the production of acids, I 

 will take, firstly, the reactions going on during the glazing 

 of pottery with salt. It is well known that although salt 

 may be volatilized unchanged, a white heat failing to 

 dissociate its elements, yet, in the presence of moisture and 

 Silica, it is readily decomposed, thus : — 



Si 0", -f H', O" + 2 Na' Cl' = Na' 2 Si G 3 + 2 H' CI', 



metasilicate of sodium and hydrochloric acid being the 

 results, the latter through its volatility escaping, and hence 

 condensable. 



If then, as suggested by that formula, we substitute, say, 

 nitrate of sodium or of potassium, we shall equally obtain 

 nitric acid, thus : — 



Si 0", + H' 2 O" +2K' ]N0 3 = K' 2 Si 3 + 2 H' N0 3 ; 



or using ferrous sulphate — at times a waste product, always 

 a cheap article — we get sulphuric acid. 



Si 0" 2 + H' 2 0" + Fe" S0 4 ■= Fe" Si 3 + H' 2 S0 4 . 



In addition to the primary object, there remains as a 

 by-product, a meta-silicate available for use in soap-making, 

 paint manufacture, or for rendering matters incombustible, 

 &c, &c. 



It may be said that in the cases of the nitric and sulphuric 

 acids the formation of anhydrides would result, but as these 

 bodies, in the presence of moisture, would re-form acids, I 

 think that point is answered. 



Suppose again that acetic acid be required, framing an 

 equation upon the same formula we get 



Si 0" 2 + H' 2 0"+ 2 (Na' C 2 H 3 2 ) = Na' 2 Si G 3 + 2 (H' C 2 H 3 2 ), 



and so on, varying the quantities of the substance to be 

 decomposed according as the acidulous radical is univalent, 

 bivalent, &c; or mono- or poly -basic in saturating power. 



